Use of polyunsaturated fatty acids for the primary prevention of major cardiovascular events

ABSTRACT

The use of polyunsaturated fatty acids of the ω-3 series such as eicosapentaenoic acid (EPA, C 20:5  ω-3), docosahexaenoic acid (DHA, C 22:6  ω-3), or their pharmaceutically acceptable derivatives is described for the primary prevention of major cardiovascular events in subjects who have not undergone previous infarct episodes.

[0001] The invention relates to the use of polyunsaturated fatty acidsfor the primary prevention of major cardiovascular events.

[0002] In particular, the invention concerns the use of polyunsaturatedfatty acids of the ω-3 series such as eicosapentaenoic acid (EPA,C_(20:5) ω-3), docosahexaenoic acid (DHA, C_(22:6) ω-3), or theirpharmaceutically acceptable derivatives, either alone or mixed together,for the primary prevention of major cardiovascular events.

[0003] The beneficial effects of polyunsaturated fatty acids of the ω-3series on multiple risk factors for cardiovascular illnesses are wellknown; for example the patents IT 1235879, U.S. Pat. No. 5,502,077, U.S.Pat. No. 5,656,667 and U.S. Pat. No. 5,698,594 refer respectively tohypertriglyceridemia, defects of the cholesterol level and hypertension.However, each of the cited documents deal with the treatment of riskfactors, not with real and proclaimed illnesses.

[0004] U.S. Pat. No. 5,753,703 describes the use of L-carnitine or itsderivatives in association with polyunsaturated fatty acids of the ω-3series or their esters, in particular EPA and DHA, for the preventionand treatment of cardiovascular disorders, vascular pathologies,diabetic peripheral neuropathies, and atherosclerotic, thromboembolyticand tissue disorders.

[0005] EP-B-0409903 describes a process for preparing high concentrationmixtures of EPA and DHA and/or their esters useful for treatinghyperlipemia and related pathologies, thrombosis, cardiac infarct,platelet aggregation, as anticoagulants in the prevention ofatherosclerosis, for the treatment of cerebral infarct, of lesions andocclusions caused by vasomotor spasms, of diabetes and itscomplications, of chronic and acute inflammations, of autoimmunesymptoms, in the prevention of side effects caused by non-steroidanti-inflammatories at the gastrointestinal level and in tumourprevention.

[0006] CN 1082909 describes compositions based on ethyl esters of EPAand DHA and other polyunsaturated fatty acids of the ω-3 series inassociation with soya phospholipids, oenothera odorata and ginkgetin, asantithrombotic and antidementia agents for treating for example dementiaand infarct of the myocardium.

[0007] U.S. Pat. No. 5,760,081 describes a method for preventingimminent fibrillation of the myocardial ventricle by intravenousinfusion of a composition containing EPA, where the subject at risk ofimminent fibrillation has already often been the protagonist of anepisode of infarct of the myocardium and where the infusion is effectedwithin 3 hours of the infarct episode, possibly using intracardiacinjection. These are always situations of extreme emergency and ofparenteral intervention, for the specific treatment of ventricularfibrillation.

[0008] Swann et al., Clinical Drug Investigation 15 (6), 473, 1998 havealso shown that the administration of EPA and DHA ethylesters, at a doseof 4 g per day, leads to a decrease in triglycerides and totalapolipoprotein C III and to an increase in antithrombin III, insubjects-with abnormal plasmatic lipoprotein symptoms and have undergonean infarct of the myocardium, they having consequently suggested that anadministration of these compositions can result in an improvement in thelipoprotein level and hence a decrease in the relative risk factors.

[0009] WO 00/48592 describes the use of a mixture of EPA and DHAethylesters in quantities greater than 25 wt. % for preventing death, inparticular “sudden death” in patients who have already suffered aninfarct of the myocardium. This therefore represents the use of saidmixture in so-called secondary death prevention, i.e. in subjects whohave already suffered infarct.

[0010] The prevention of cardiovascular damage by means of fatty acidmixtures described in the state of the art is therefore focused on“secondary” prevention of cardiovascular damage. i.e. aimed atprotecting a subject who has already suffered an infarct, whereas“primary” prevention of major cardiovascular events, i.e. prevention insubjects who, while affected by various pathologies of thecardiocirculatory and/or cardiorespiratory systems, have not yetsuffered an infarct episode, constitutes a technical problem which isstill felt in this sector.

[0011] According to a first aspect the invention relates to the use ofpolyunsaturated fatty acids of the ω-3 series for the preparation of adrug useful in the primary prevention of a major cardiovascular event insubjects who have not undergone previous infarct episodes, wherein thefatty acids comprise eicosapentaenoic acid (EPA) and/or docosahexaenoicacid (DHA) and/or at least one pharmaceutically acceptable derivativethereof, in quantities greater than or equal to 25 wt % on the totalfatty acid weight.

[0012] In the present description, the expression “polyunsaturated fattyacids of the ω-3 series” means those long-chain polyunsaturated fattyacids, generally C₁₆-C₂₄, containing fish oils, in particular thosehaving a C₂₀-C₂₂ chain, which are predominant in purification processes.

[0013] The expression “major cardiovascular event” means in particularthose events which involve reversible or irreversible cardiovasculardamage, such as infarct of the myocardium and of individual coronarybranches, death from cardiac causes, sudden death, etc., besides toinfarct, broadly speaking, ictus etc., and those conditions prodromal tosuch major events, such as myocardial fibrillation, atrial and/orventricular fibrillation, etc. Said major cardiovascular events areusually induced by various cardiocirculatory and cardiorespiratorypathologies such as coronary ischemic illness not displayed by previousinfarct episodes, and by serious hypoxic/anoxic states caused by asudden lack of oxygen (for example during anesthesia, surgery, etc.),possibly in the presence of conditions which contemplate an increase inthe oxygen requirement (accentuated physical stress, drug abuse, acutehypertensive crises, etc.) and analogous acute and chronic pathologiesdue to cardiac defects of electrical and/or mechanical type.

[0014] The subjects affected by pathologies of the cardiocirculatory andcardiorespiratory system, hence not simply at prospective risk due tohypertriglyceridemia, hypertension or other, are representative ofsubjects definable at various levels as cardiopaths, by being affected,for example, by coronary ischemia detectable by coronarography,scintigraphy of the myocardium, electrocardiogram (ECG) under stress,etc., against which interventions of revascularization (angioplasty) orother possible pharmacological or invasive treatments have beenproposed, and of subjects affected by electrical hyperexcitability ofthe myocardium cells, disorder of the diffusion of electrical excitementor of electrical conduction (arrhythmia, fibrillation, etc.) or by otherdefects of mechanical type (cardiac insufficiency, decompensation),possibly aggravated by concomitant pathologies such as diabetes.

[0015] The use of polyunsaturated fatty acids of the w-3 seriesaccording to the invention is particularly indicated if the occurrenceof a major event is predicted, such as an infarct, in particular of themyocardium, death from a cardiological cause, or sudden death, and wheresuch an occurrence takes place in cardiopathic subjects affected, forexample, by coronary ischemia, arrhythmia, atrial and/or ventricularfibrillation, electrical hyperexcitability of the myocardium cells,disorder of the diffusion of electrical excitement or of electricalconduction of the myocardium, or cardiac disorders of mechanical type,for example cardiac insufficiency or cardiac decompensation, possiblyaffected by diabetic pathology concomitant with the cardiopathy.

[0016] Preferably, the content of EPA and/or DHA and/or of the at leastone derivative thereof is between 50% and 100%, in particular between75% and 95%, and more preferably about 85% by weight on the total fattyacid weight. The preferred EPA and/or DHA derivatives are selected fromthe corresponding C₁-C₃ alkyl esters and/or from their salts withpharmaceutically acceptable bases such as sodium hydroxide, lysine,arginine or aminoalcohols such as choline. The ethylesters of EPA andDHA, in particular mixed together in any concentration and percentage,are the most preferred.

[0017] The drug is administered preferably orally, in particular in theform of soft gelatin capsules. For oral use, the unit dose generallycomprises 100-1000 mg of polyunsaturated fatty acids of the ω-3 series,preferably 500-1000 mg or 300-500 mg, the total dose being usuallyaround 0.1-3.0 g per day or per alternate day, according to the caseconcerned, and preferably 0.3-2.0 g per day and in particular 1.0 g perday. The effective dose of the drug suitable for the use of theinvention is 1.0-60.0 mg/kg of body weight/day.

[0018] Other types of formulation for oral administration are alsosuitable for the purposes of the invention; for example hard capsules ortablets, in which the polyunsaturated fatty acids are adsorbed on solidsupports. It is also possible to use emulsions, granulates in dispersingexcipients, syrups, droplets, etc., and other forms of administrationable to ensure systemic absorption of the drug, such as sterilesolutions or emulsions and the like, suitable for parenteral use and thelike, as evaluated by the expert of the art, on the basis of theseverity of the pathology.

[0019] Those compositions illustrated in the European Pharmacopea 2000(EuPh. 2000), containing quantities greater than or equal to 80 wt % ofmixtures of EPA and DHA ethylesters and a total of ω-3 polyunsaturatedfatty acid ethylesters greater than or equal to 90 wt % are alsosuitable for the purposes of the present invention.

[0020] The aforestated compositions and the drugs suitable for the useof the invention can be prepared by methods known to the expert of theart, such as those described in U.S. Pat. No. 5,130,061, WO 89/11521, IT1235879, JP 02/25447, which are incorporated into the presentdescription with regard to the method of preparation.

[0021] The drug suitable for use according to the present invention canalso comprise other active principles and/or drugs, in association,possessing activity complementary to or synergic with that of the drugsuitable for use according to the invention, and also at least onepharmaceutically acceptable vehicle and/or one diluent and/or onesurfactant and/or one thickener and/or one binder and/or one lubricantand/or one aromatizer and/or one colorant and/or one stabilizer and thelike, which can easily be selected by the expert of the art. Of thestabilizers, antioxidants such as vitamin E (tocopherol), ascorbylpalmitate, ascorbic acid, hydroxytoluene and the like, which can beeasily selected by the expert of the art, are particularly preferred.

[0022] According to another aspect, the invention relates to a methodfor the primary prevention of a major cardiovascular event in subjectswho have not undergone previous infarct episodes, comprising theadministration of an effective dose of a drug comprising polyunsaturatedfatty acids of the ω-3 series as hereinbefore described. In particular,the method of the invention is indicated whenever the occurrence of amajor cardiac event is predicted such as an infarct, in particular ofthe myocardium, death from a cardiological cause or sudden death.

[0023] The following examples illustrate the invention but withoutlimiting it.

[0024] The compositions illustrated in the following table were preparedby the methods described in U.S. Pat. No. 5,130,061 (compositions A, C,D, F), IT 1235879 (composition B), JP 02/25447 (composition E) and WO89/11521 (compositions G-I).

[0025] All the quantities indicated in the following table expresspercentages by weight on the total weight of polyunsaturated fatty acidsof the ω-3 series. A¹ B¹ C¹ D¹ E¹ F¹ G¹ H² I³EPA >40 >44 >40 >25 >80 >20 <15 >40 >40 DHA >34 >30 >34 >20<10 >25 >80 >30 >30 EPA + DHA >85 >80 >80 >50 >80 >50 >85 >80 >80esters⁴ >3 — tot.esters⁵ >90 α-tocopherol 0.03 0.03 0.1 0.3 0.1 0.3 0.030.1 0.1

EXAMPLE 2

[0026] The compositions illustrated in the following table, relative tosoft gelatin capsules containing 1 g of polyunsaturated fatty acid ethylesters, were prepared by methods known in the art. A (mg) B (mg) C (mg)EPA¹ 525 — >400 DHA¹ 315 — >340 EPA + DHA 850 >800 Total ω-3¹ — >900d-α-tocopherol 4 I.U. — 4 I.U. d,I-α-tocopherol 0.3 gelatin 246 — 246gelatin succinate 233 glycerol 118 67 118 OFR 2.27 — 2.27 OFG 1.27 1.27SOB 1.09 SPOB 0.54

[0027] Pharmacological Activity

[0028] The pharmacological activity of the compositions of the inventionwas evaluated on the basis of tests carried out on small laboratoryanimals (mouse, guinea pig, rat); this experimental model was chosenbecause of the ability to make rapid and highly reproducibleverifications and to use a sufficiently large number of animals, such asto enable a statistically accurate evaluation of the results to be madewithout exposing the patient to risk, with evident ethical implications.

[0029] During the course of these tests, groups of animals werepretreated repeatedly with the formulations of Examples 1 and 2 andthen, in comparison with untreated groups, were subjected to the actionof cardiotoxic or respiration-depressive substances, then visuallymeasuring protection against death, or—by means of elettrocardiographicrecording—measuring the delay in the start of initial cardiac arrhythmiaor of ventricular tachycardia and above all the delay in or theprevention of animal death due to sudden cardiac and/or respiratoryarrest.

[0030] Using an analogous experimental model, cardiological pathology,coronary ischemia and a state of infarct were induced by coronaryligature instead of by cardiotoxic agents.

[0031] Test 1

[0032] The experimental sudden death model was obtained by cardiacarrest induced by intravenous (i.v.) administration of a cardiotoxicagent (ouabain). In preliminary tests, various doses of ouabain wereadministered to non-anesthetized guinea pigs of both sexes of weight300-380 g, in order to determine the minimum lethal dose for 100% of theanimals within 15 minutes from i.v. injection (240 mg/kg, intravenouslyadministered over 3 minutes).

[0033] Two groups of 20 guinea pigs were then treated with 50 and 100mg/kg of a composition containing 85% of EPA and DHA ethylesters (Ex. 1,composition A) for 10 days. After 2 hours from the last administrationthe two groups of guinea pigs and a further untreated group, used ascontrol, were treated with 240 mg/kg i.v. of ouabain, recordingmortality within the subsequent 15 minutes.

[0034] Results expressed as survivors after 15 minutes: Controls 00/2050 mg/kg 11/20 100 mg/kg 16/20

[0035] Test 2

[0036] 3 groups of 15 male mice, initial weight 25-32 g, were treatedorally for 15 days with physiological solution (control group) and with50 or 100 mg/kg of a composition containing 85% of EPA and DHAethylesters (Ex. 1, composition A).

[0037] 60 minutes after the end of the last treatment, the animals ofall the groups were treated with sodium pentabarbital i.p. (50 mg/kg)and then with aconitine i.v. (0.25 mg/kg). The times of appearance ofcardiac arrhythmia (deviation >5 seconds from the normal sinus rhythm),of ventricular fibrillation and of cardiac arrest were determined byelectrocardiograph recording. Results expressed as mean±standarddeviation (seconds) on the positive animals. T t₁ (sec) t₂ (sec) t₃(sec) S C 123 ± 12 174 ± 7 214 ± 32 00/15 (15/15) (15/15) (15/15) 50mg/kg 168 ± 8 235 ± 16 350 ± 26 09/15 (08/15) (06/15) (06/15) 100 mg/kg195 ± 15 284 ± 18 378 ± 35 12/15 (05/15) (03/15) (03/15)

[0038] Test 3

[0039] 2 groups of 20 male rats, initial weight 310-350 g, were treatedorally for 15 days with physiological solution (control group) and with100 mg/kg of a composition containing >80% of EPA and DHA ethylesters(Ex. 1, composition B). The rats of the 2 groups were then anesthetizedwith sodium pentobarbital i.p. (50 mg/kg), then subjected to ligature ofthe left anterior descending coronary artery, which allows blood flow tothe left ventricle, so inducing an acute ischemic state of themyocardium. During the subsequent 15 minutes the duration of ventricularfibrillation was recorded by ECG, this either resolving itselfspontaneously or concluding with sudden death.

[0040] Results T F (sec) Mortality S (%) C 190 ± 24 16/20 20 (18/20) 100mg/kg 55 ± 5 01/20 95 (04/20)

[0041] Test 4

[0042] The experimental model implemented for sudden death byrespiratory arrest involves its inducement by chloroform inhalation.

[0043] 4 groups of 10 male mice, initial weight 26-32 g, were treatedorally for 5 days with physiological solution (control group) and with10, 30 and 60 mg/kg of a composition containing 80% of EPA and DHAethylesters (Ex. 1, composition C).

[0044] 60 minutes after the end of the last treatment, the animals wereexposed to chloroform until respiratory arrest had occurred. The animalswere then checked for tachyarrhythmia of the myocardium induced by thehypoxic state, this either resolving itself spontaneously within thenext 15 minutes or concluding with death of the animal.

[0045] Results Protection from Treatment tachyarrhythmia SurvivalsControl 00/10 03/10 10 mg/kg 04/10 06/10 30 mg/kg 07/10 08/10 60 mg/kg09/10 10/10

[0046] Test 5

[0047] 2 groups of 20 male rats were treated as on Test 3, withphysiological solution and with the same EPA and DHA composition(Example 1, composition B).

[0048] Ligature of the circumflex coronary artery was then effected,with consequent reduction in the contractile capacity of the myocardiumand of the ejection fraction. The mortality of 18/20 animals of thecontrol group fell to 4/20 of the treated group, during the course ofthe subsequent 60 minutes.

[0049] The clinical results of the tests demonstrate the pharmacologicalactivity of the polyunsaturated fatty acids of the ω-3 series in theprimary prevention of major cardiovascular events in subjects who havenot undergone previous infarct episodes.

1. Use of polyunsaturated fatty acids of the ω-3 series for thepreparation of a drug useful in the primary prevention of a majorcardiovascular event in subjects who have not undergone previous infarctepisodes, wherein the fatty acids comprise eicosapentaenoic acid (EPA)and/or docosahexaenoic acid (DHA) and/or at least one pharmaceuticallyacceptable derivative thereof, in quantities greater than or equal to 25wt % on the total fatty acid weight.
 2. Use as claimed in claim 1,wherein the major cardiovascular event is infarct.
 3. Use as claimed inclaim 1, wherein the major cardiovascular event is infarct of themyocardium.
 4. Use as claimed in claim 1, wherein the majorcardiovascular event is death from a cardiological cause.
 5. Use asclaimed in claim 1, wherein the major cardiovascular event is suddendeath.
 6. Use as claimed in any one of the preceding claims, wherein thesubjects are cardiopathic.
 7. Use as claimed in any one of the precedingclaims, wherein the subjects are affected by coronary ischemia.
 8. Useas claimed in any one of the preceding claims, wherein the subjects areaffected by arrhythmia, fibrillation, electrical hyperexcitability ofthe myocardium cells, disorder of diffusion of the electrical excitementand of electrical conduction of the myocardium.
 9. Use as claimed in anyone of the preceding claims, wherein the subjects are affected bycardiac disorders of mechanical type.
 10. Use as claimed in any one ofthe preceding claims, wherein the subjects are affected by cardiacinsufficiency.
 11. Use as claimed in any one of the preceding claims,wherein the subjects are affected by cardiac decompensation.
 12. Use asclaimed in any one of claims from 6 to 11, wherein the subjects areaffected by diabetic pathology concomitant with cardiopathy.
 13. Use asclaimed in any one of the preceding claims, wherein the content of EPAand/or DHA and/or of the at least one derivative thereof is between 50%and 100% by weight on the total fatty acid weight.
 14. Use as claimed inany one of the preceding claims, wherein the content of EPA and/or DHAand/or of the at least one derivative thereof is between 75% and 95% byweight on the total fatty acid weight.
 15. Use as claimed in any one ofthe preceding claims, wherein the content of EPA and/or DHA and/or ofthe at least one derivative thereof is equal to about 85% by weight onthe total fatty acid weight.
 16. Use as claimed in any one of thepreceding claims, wherein the at least one derivative of EPA and/or DHAis selected from the corresponding C₁-C₃ alkyl esters and/or acidsand/or salts with pharmaceutically acceptable bases.
 17. Use as claimedin any one of the preceding claims, wherein the drug comprises EPAethylester and/or DHA ethylester.
 18. Use as claimed in any one of thepreceding claims, wherein the drug is administered orally.
 19. Use asclaimed in any one of the preceding claims, wherein the drug is in theform of soft gelatin capsules.
 20. Use as claimed in any one of thepreceding claims, wherein the drug is administered at a dose of 0.1-3.0g per day.
 21. Use as claimed in any one of the preceding claims,wherein the drug is administered at a dose of 0.3-2.0 g per day.
 22. Useas claimed in any one of the preceding claims, wherein the drug isadministered at a dose of 1.0 g per day.
 23. A method for the primaryprevention of a major cardiovascular event in subjects who have notundergone previous infarct episodes, comprising the administration of aneffective dose of a drug claimed in any one of the preceding claims. 24.A method as claimed in the preceding claim, wherein the majorcardiovascular event is infarct.
 25. A method as claimed in claim 23,wherein the major cardiovascular event is infarct of the myocardium. 26.A method as claimed in claim 23, wherein the major cardiovascular eventis death from a cardiological cause.
 27. A method as claimed in claim23, wherein the major cardiovascular event is sudden death.